(a) Filing offices.--Except as otherwise provided in subsection (b), if the local law of this Commonwealth governs perfection of a security interest or agricultural lien, the office in which to file a financing statement to perfect the security interest or agricultural lien is one of the following:
(1) The office designated for the filing or recording of a record of a mortgage on the related real property if:
(i) the collateral is as-extracted collateral or timber to be cut; or
(ii) the financing statement is filed as a fixture filing and the collateral is goods which are or are to become fixtures.
(2) The office of the Secretary of the Commonwealth in all other cases, including a case in which the collateral is goods which are or are to become fixtures and the financing statement is not filed as a fixture filing.
(b) Filing office for transmitting utilities.--The office in which to file a financing statement to perfect a security interest in collateral, including fixtures, of a transmitting utility is the office of the Secretary of the Commonwealth. The financing statement also constitutes a fixture filing as to the collateral indicated in the financing statement which is or is to become fixtures.